The subject matter disclosed herein relates to rotary machines and, more particularly, to systems and devices for sealing and/or substantially fluidly isolating portions of a rotary machine.
The design and operation of some rotary machines (e.g. steam turbines) include the use of seal assemblies. These seal assemblies may include any number of segments/elements which are assembled between portions of the turbine, the elements being disposed relative one another so as to form a seal or barrier. During operation, these seal assemblies may substantially separate stationary and/or rotary portions of the turbine. However, variances in thermal expansion rates and steam turbine operating temperatures may require clearances between each of the elements of these seal assemblies. These clearances between the seal assembly elements may create gaps between those elements, thereby enabling leakage of a fluid through the seal assembly. This leakage may damage components in the turbine and/or decrease the efficiency of the steam turbine. Some turbines may limit leakage through these thermal spaces by placing a separate sealing strip at the gap in between elements of the seal assembly, thereby limiting axial leakage. However, this sealing strip fails to prevent radial leakage through the thermal gap between segments of the seal assembly.